I don't "rag it" very often, and I doubt it's caused by damper resistance, because the bend is away from the backplate. Having given it some thought I think it's more likely due to axle wind up when accelerating hard. Without anti-tramp bars the lower bracket will resist axle rotation once the slack in the bush is taken up, and a bump in the road will really put a heavy shock through it. The picture of the one which has split vertically seems to support this theory. I might consider a Mulfab anti-tramp set up........
